SpaceX Dragon becomes the third reusable spacecraft to refly into orbit.
Today's mission is the latest in a series of historic firsts for SpaceX, the private spaceflight company founded by billionaire entrepreneur Elon Musk. In March, the company successfully launched and landed a used rocket booster for the first time. SpaceX is also the first and only company to have landed a rocket booster during an orbital mission (though Jeff Bezos' Blue Origin has achieved this multiple times on suborbital journeys). And in 2012, SpaceX's Dragon capsule became the first private spacecraft to dock at the ISS.